Road strip



J. M. PAVER June 27, 1939.

ROAD STRIP Filed Dec. 7. 1936 2 Sheets-Sheet 1 INVENTOR JOHN M. PAVERBYMCMV ATTORNEY J. M. PAVER ROAD STRIP June 27, 1939.

Filed Dec. '7. 1936 2 Sheets-Sheet 2 R E RV OA .Y MPM R WMWO T mN T H AO .J

Patented June 27, 1939 UNITED STATES PATE NT OFFICE ROAD STRIE John M.'P'aver, New York, NJ Y. Application December. 7, 1936, Serial No.114,597

5 Claims;

section of a strip apof connectingterminals Fig. fl is aI transversesection of thev strip taken on the plane 4-4-'of Fig. 2;

Figs; 5- and .6 are transverse sections'of the strip illustrating theaction of a1 vehicle-Wheel on the strip; and

Figs. '7, 8 and 9 illustrate another method of preventingy displacementof the spacers, Figs. 8 and 9 being transverse sections on-the planes8'-8 andfS-S respectively of Fig. 72

The illustrative road' strip I0 is particularly advantageous inconnection with the study or counting of vehicular trailic since itlpermits installation ofthe traic counting apparatus quickly at strategicpoints without alteringor impair- 3o ing the-road surface and withoutspecial structure lin the pavement to receive it. Indeed`itmay beinstalled practically without traffic.

As'here shown, the strip comprises a` pair of interruptionv of spacedelectrical conductors, at least one of which is movable relatively tothe other and is'resilientY so that it will not be permanently distortedby the passing traic. In the presentv instance these conductors are inthe form of spaced strips I I and I2 of resilient metal, such asSwedishhigh carbon ribbon'steel which will not be permanently distortedor deformed by the forcesexertedthere'- on by vehicle Wheels.

be somewhat narrower than the bottom strip because of the taperingcharacter of the upper.

nevertheless, should advantageously be resilient to avoid beingdistorted by a rough road surface, is of an inch in width and .020 of aninch in thickness.

The strips are held in separated relation by resection of the end ofthe.

Such strips maybe' aboutv 1?/8 of an inch in width, although thei upperstripV (Cl. ZOU-86) silient or compressible spacedv members here' shownin the form of short, soft rubber blocks I3 whichA are preferablysecured to'one of the metal strips to maintain their spacing.Theupper'sur.- face I4 of the spacers I3 is preferably longitudi 5-nally rounded to conform approximately to the curvature assumed by theupper strip II when it is depressed by a vehicle wheel, as indicated by*dotted lines I5 (Fig. 2). This avoids concentra-v tion of stressen themetal strip which would l0' otherwise occur ifY the spacer blocks hadsharp corners.

The spacers I3 may advantageously be about' l/2 inch long and preferablyhave gaps IB ofaboutY 1 inch in length; between them. The length and 15spacingofV the spacersl 3 depend somewhat on the' stiffness of the upperconductor II, aswell a's'the character of and pressure deliveredby'thevehicle" tires. The present arrangement hasbeen found to be-eicient.

Theconductors and the intervening'spacers'are housed within aprotective'covering in theV form of a rubber sheath or strip I'Ihavingf'alongitudinallyV extendingconduit I8 for the conductors. Thestrip I'I is preferably formedl with a relatively wide base I 9 (in thiscase' about 11/2 inches wide) by means of which the strip may becemented to the road surface; The stripis relatively thin andits uppersurface 2U is preferably tapering incontourfso'as to minimize the'obstruction present to the. passage ofvehiclewheels and thereby tominimize the side thrust delivered-to the strip. The maximum thicknessof the strip (which occurs along its center line) may be less' than 1/4of an inch and in this case is .2' of" an inch. The middle portion 2I ofthe top of the channel enclosing the contact stripsis somewhat thickened(see Figs. 4 and 5); and at 22 (at the sides of the channel) the wall ismade relativelyY thin so asto yield a bulge readily under tire pressure,to cause the thicker central'portion 2| to bulge downwardly (see Fig. 5)to depress the upper contact strip so as to make a surface contactinstead of a point contact. Figs; 5 and 6 illustrate both how the actionof Ya wheel in passing` over theY strip slightly displaces the upperstrip to cause rubbing which improves tl'ie electrical contact and howthe strips arecaused to separate over their entire contacting surfaces(asY contrasted with a tilting separationwhich would concentrate at onepoint the actual breaking of contact), therebyavoiding destructivesparking.

The strip may be cemented4 across a roadway by means ofla plastic cementsuch as ordinaryVV 55g rubber tire cement, which will hold the stripwith firmness, yet permit its removal without destruction of the strip.The rubber cement is quick drying and permits the laying of a strip withpractically no interference with traiiic. The 'conductors II and I2 are,of course, connected 'with the traic counting apparatus 23 which may beof any appropriate design, such as that disclosed in my copendingapplication, Serial No. 700,449, now Patent No. 2,067,336, dated Jan.l2, 1937 of which the present application is a continuation in part.

The road strip may advantageously be made up with long spacer strips 24having such arrangement relative to the short spacers I3 as to make itcertain that the wheels on at least one side of a vehicle will pass overon that portion of the strip vwherein the conductor strips II and I2 areseparated by short spacers (see Fig. l). The long spacer strips have anumber of advantages. For example, adjacent the side or curb 25 of aroadway, where parking is permitted, the elongated spacer strips preventa continuous electrical contact in the event a vehicle is parked with awheel resting on the contact strip. Adjacent the side of the roadway,the elongated strips 24 should be slightly in excess of the vehiclewheel gauge. vSince a moving vehicle will ordinarily not travel in closeproximity to the curb, its outer wheels will, of course, make anelectrical contact in the live section 26 of the strip just beyond theend of the curb spacer strip 24. Most States require that when parked,the vehicle wheels must not be more than 6 inches from the curb. If thecurb spacer strip 24 be about 62 inches in length (which is about 6inches greater than the tread gauge of the ordinary vehicle wheels) avehicle may safely be parked along the curb without danger of causing anelectrical contact. On the other hand, the strip will not be long enoughto prevent moving vehicles from making an electrical contact beyond theend of the spacer strip.

The elongated spacer also advantageously prevents a double count whichwould otherwise result from vehicles traveling diagonally across theroad strip. For such purpose, dead sections 21 alternate with livesections 26, the dead sections being those embraced within the length ofan elongated spacer 24 and the live sections being those having theshort spacers I3. In such an arrangement, the live sections 26 should besomewhat in excess of the vehicle tread guage (a section of about inchesin length being satisfactory) and the dead sections 21 should be lessthan the vehicle tread gauge in length (a length of about 50 inchesbeing satisfactory). The exact length of the intermediate live and deadsections 26 and 21 will vary somewhat depending upon the width of theroad. The space between the inner ends of the opposite dead curbsections 26 should be divided into alternate live and dead sections insuch a way that the live sections should exceed the vehicle tread gauge,the dead sections comprising the remainder but always being less thanthe vehicle tread gauge.

Where it is desirable to make a separate count of vehicles traveling ineach direction on the roadway, independent road strips or circuits andcounting apparatus are employed for each half of the roadway. In thatevent, the live portions of the road strips each should terminate shortof thev center of the roadway to leave a dead gap slightly in excess ofa vehicle tread gauge, thereby making it impossible for a vehicletraveling down the middle of the road to register in both countingunits. If both sets of counting apparatus be located on one side of theroad, the road strip may be made physically continuous and the deadsection at the middle of the road may be formed simply by an elongatedspacer strip of the appropriate length. Lead wires from the outer halfof the road strip may be carried through the other half of the roadstrip to the counting apparatus as disclosed in my copendingapplication.

The spacers, and particularly the spacers I3 may advantageously bemechanically connected with one of the conductor strips (in this casethe bottom conductor strip) so as to obviate the necessity of anadhesive, some of which might creep between the conductor strips andtemporarily cement them together when they are brought into contact by avehicle. One form of mechanical connection is illustrated in Figs. 2 and4,where in the bottom strip I2 is provided with longitudinalperforations through which portions 30 of the rubber body of the spacersmay be pressed or extruded and if necessary vulcanized, to act as rivetsin holding the spacers in place.

Figs. 7, 8 and 9 illustrate a diierent method of preventing displacementof the spacers. Here the spacing elements 3| are in effect an integralpart of a rubber tubular member 32 which surrounds a contact strip, inthis case the lower strip, I2, and are spaced to provide the usual gapsI6. Preferably the spacer unit is formed by vulcanizing or otherwisesecuring the side edges of separately formed spacer blocks to a rubbercarrying strip which lies under the lower contact strip. Theintermediate portions of the blocks should of course be free to provideslots or passages through which the contact strip may be threaded. v'Ihespacer unit may, of course, be formed from a tube in which sections hadbeen cut out or omitted to provide gaps The dead or inactive sections ofthe strip are formed by surrounding a contact, in this case the lowerstrip, I2, by an imperforate tube 33 of rubber or the like whichcompletely envelops the contact strip throughout the extent of theinactive sections.

In assembling a road strip, the aforesaid spacer units are cut to thelengths represented by the live and dead sections of the strip and thenslipped over the lower Contact strip, after which the latter strip andthe upper contact strip are assembled and inserted in the outer sheathI'I. The aforesaid arrangement eiectively prevents displacement not onlyof the short spacers but the long spacer in the dead sections of theroad strip.

The rubber covering II of the road strip may advantageously be formed byan extrusion process into strips of indefinite length, which may be cutto such length as required by the roadway. The rubber from which thestrip I1 is made should be soft and of good quality, so as to withstandweathering and repeated impacts of the vehicle wheels without crackingor other damage.

Obviously the invention is not limited to the details of theillustrative embodiment, since these may be variously modified.Moreover, it is not indispensable that all features of the invention beused conjointly since various features may be used to advantage indifferent combinations and sub-combinations.

Having described my invention, I claim:

l. An elongated contact strip adapted to be placed on top of the surfaceof a roadway and comprising in combination an elongated electricalconductor made of a strip of resilient metal of such character as not tobe permanently deformed by the forces exerted b-y heavy passing traflc,a return conductor and spaced insulating devices between said conductorsfor holding the same out of electrical contact with each other, theupper conductor being adapted to be deflected by the forces of traino tobring said conductors into electrical contact, a cover around saidconductors to protect the same and exclude dirt, said cover having arelatively wide and flexible bottom whereby it may be laid upon andcemented to the surface of the road and being relatively low in heightand having the upper surfaces of its side margins beveled so as tominimize the tendency of rapidly moving trac to displace said strip.

2. A road strip comprising in combination separated upper and lowermetallic contact strips having spaced insulating devices between them tohold them normally separated, said strips being adapted to extend acrossa roadway and to be brought into electrical contact between saidinsulating devices by pressure of a vehicle wheel, a tubular rubbersheathing having a relatively low height around said strips, said stripsbeing located along the central line of said sheathing inside itstubular portion, said sheathing having a wide base for attachmentdirectly to a road surface and having its side margins tapered toprovide thin side edges, said sheathing having a relatively thin walladjacent the edges of said strips adapted to ilex readily under avehicle wheel running upon said strip, the tapered contour of said sidemargins permitting a vehicle wheel to cross the same without substantiallateral thrust and the pressure of the wheel upon said margins servingto anchor the strip against lateral movement as the wheel passes overthe thicker central portion of said strip.

3. A road strip for use in traic registering apparatus comprising incombination upper and lower metallic contact strips adapted to extendacross a roadway and to be brought into electrical contact by thepressure of a vehicle wheel, spacer strips between said contact stripsof a length less than vehicle wheel gauge, said spacer strips beingseparated longitudinally by distances greater than vehicle wheel gauge,said Contact strips having short insulating separators between them inthe regions between said spacer strips, said insulating separators beingspaced so as to allow the upper contact strip to be depressed intocontact with the lower contact strip under pressure of a vehicle] wheel,and a flexible sheathing covering said strips and having a wide baseadapted to be cemented directly to a road surface.

4. A road strip for use in traic registering apparatus comprising incombination a plurality of longitudinally extending contact sectionshaving upper and lower metallic contact strips adapted to be broughtinto Aelectrical contact by the pressure of a vehicle wheel, saidcontact sections being slightly longer than vehicle wheel gauge andbeing longitudinally separated by a distance slightly less than vehiclewheel gauge whereby to prevent erroneous traffic registration byvehicles crossing the strip diagonally, said sections being covered by ailexible protective covering having a relatively wide base by which thesame may be applied directly to the surface of the roadway.

5. A road strip comprising in combination upper and lower metalliccontact strips adapted to extend across a roadway, a plurality ofinsulating spacers between said contact strips and being spaced apartsufficiently to permit the upper contact strip to be depressed intocontact with the lower strip under pressure of a vehicle wheel, spacerstrips of a length slightly greater than vehicle wheel gauge beinglocated between said contact strips adjacent the side edges of theroadway to prevent contact between said contact strips by a Vehicleparked along the edge of the roadway, and a iiexible coveringsurrounding said contact strips.

JOHN M. PAVER.

